Republican presidential candidate Mitt Romney wants to immediately restore the Pentagon’s base budget to levels proposed by former Defense Secretary Robert Gates in 2012 before last year’s Budget Control Act slashed $259 billion from planned spending, according to campaign advisers.

A Romney administration would allot 4 percent of the U.S. gross domestic product (GDP) to the defense base budget, said Roger Zakheim, one of the former Massachusetts governor’s senior defense advisers, at a Thursday breakfast with reporters in Washington. Zakheim is on leave from his job as deputy staff director and general counsel of the House Armed Services Committee.

Gates’ fiscal 2012 Pentagon budget proposal called for $2.99 trillion in defense spending from 2013 to 2017. That projection was cut by $259 billion after Congress passed the Budget Control Act in 2011.

Romney believes additional cuts mandated under the Budget Control Act, known as sequestration, also need to be reversed, his advisers said.

The fiscal 2013 Pentagon budget proposal is 3.3 percent of GDP.

Dov Zakheim — Roger Zakheim’s father and another senior Romney adviser who has served in numerous defense positions under Republican presidents, including Pentagon comptroller under President George W. Bush — acknowledged that Romney would not necessarily be able to achieve the 4 percent GDP level of spending in his first term as president.

“We’re not going to come in with this massive supplemental” spending measure, he said.

Specific defense budget numbers would rely on GDP levels. So if the GDP grows quickly, the defense budget would grow faster. If it does not grow as fast, the Defense Department budget would be smaller.

“I can’t predict to you what the denominator is,” Dov Zakheim said, when asked about a specific level.

The defense budget needs at least 2 percent real growth each year or procurement and research and development historically is cut, Roger Zakheim said.

As for policy, Romney believes the Pentagon should be focused on the Asia-Pacific, Roger Zakheim said. That said, the campaign believes the Obama administration’s strategy to focus heavily on the Pacific and Middle East is not achievable due to a planned truncation in force structure.

Roger Zakheim said Romney’s heavy focus on the Middle East during campaign speeches is the result of high-profile issues in the region, including the killing of Christopher Stevens, the U.S. ambassador to Libya.

While the Romney campaign has spoken, at length, about plans for the Navy, it has said little about plans other services.

Roger Zakheim said, if elected, Romney would focus on the modernization of Air Force fighter and bomber aircraft. Roger Zakheim spoke of speeding up the decision on a new Air Force long-range bomber as well as funding the Lockheed Martin-built F-35 joint strike fighter.

“We need to get strong leadership in the Air Force, not only on the military side, but also strong civilian leadership across” all the services, he said.

As for acquisition, Roger Zakheim said a Romney Pentagon would focus on strong civilian leadership and shortening the development phases of weapon programs.

Dov Zakheim said the size of the civil service, particularly in the acquisition ranks, needs to shrink.

“The acquisition corps is out of balance,” he said. “On the one hand it’s too large and on the other hand you don’t have enough oversight.”